The invention relates to a method for measuring an average velocity pressure of a pipe, and more particularly to a method for measuring an average velocity pressure of a stack.
With reference to FIG. 1, conventional method for measuring an average velocity pressure, such as Taiwan Patent No. 517840, comprises: forming two openings on a pipe, obtaining a total pressure and a static pressure in a pipe separately through a total pressure detecting tube 321 and a static pressure detecting tube 322 passing the openings, and obtaining the average velocity pressure by subtracting the static pressure from the total pressure.
When the pipe transmits corrosive gas, the inner wall thereof must be subject to a corrosion-resistant process. The cost of the corrosion-resistant process, however, increases with the number of the openings. Additionally, the openings decrease the structural integrity and life of the pipe.